Pennies Earned Posted October 31, 2009 Share Posted October 31, 2009 (edited) Exactly what the title says. How many turns out should my Air/Fuel screw be. EA82 Hitachi Edited October 31, 2009 by Pennies Earned Link to comment Share on other sites More sharing options...
ferox Posted October 31, 2009 Share Posted October 31, 2009 (edited) Air/Fuel screw is dependent on the timing and idle mixture. Make sure the timing is correct. On ea81s I think the idle mixture screw is usually turned out between 1.75-2.5 turns. I am sure ea82s are similar. It should get you in the ball park anyway. Then turn the air/fuel mixture screw right or left to bring the rpms into spec. If I am remembering correctly, turning the A/F screw clockwise increases rpms. There is a point where you unscrew it too much and it won't do anything to the idle speed. If that happens and your idle speed is still to high [EDIT-screw it back in until the rpms react to it] it means you have to adjust your idle mixture some more or there is some other problem. But as far as I know there isn't a set distance or number of turns for the A/F screw. Someone will correct me if I am wrong. Edited October 31, 2009 by ferox Link to comment Share on other sites More sharing options...
Pennies Earned Posted October 31, 2009 Author Share Posted October 31, 2009 How do I go about timing this puppy? All I've been messing with are the idle screw and the air/fuel screw. Link to comment Share on other sites More sharing options...
GeneralDisorder Posted October 31, 2009 Share Posted October 31, 2009 Idle speed and mixture are a balancing act. Generally speaking, the idle speed screw should be set as low as possible to maintain a good solid idle and smooth progression. Start with the mixture screw about 2.5 turns out. Then set your idle speed to 700 +/- 100 RPM. Adjust the idle screw IN till it begins to stumble and the engine changes pitch. Now count the turns OUT till it does something similar. Set it just about in the middle, maybe a schosh on the rich side. Then set the idle speed screw a second time to 700 +/- 100. Then tweak the mixture till you like how it runs and the progression from idle to primary is smooth. If you can't get a smooth progression then you probably have vacuum leaks or other carb issues besides the idle settings. To set the timing, get a timing light and turn the distributor till you show 8 degrees BTDC on the flywheel. If you don't have a light then set it with the engine not running. Just set the flywheel to 8* BTDC, then adjust the distributor till the rotor is pointing at the #1 plug tower. If you have a good eye you can hit 8* within about half a degree. Good enough anyway. If it was way off before you set it, then you probably will need to adjust the idle speed and mixture again. GD Link to comment Share on other sites More sharing options...
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